The United Nations refugee agency says, under its voluntary repatriation program, nearly 500,000 Afghans have returned to their homeland this year from neighboring Pakistan and Iran.

International efforts to establish peace and rebuild war-ravaged Afghanistan have encouraged more than 2.2 million Afghan refugees to return home during the past two years. Most of them came back from refugee camps in neighboring Pakistan.

After the fall of the Taleban regime in late 2001, the United Nations created a program to help returning Afghans, giving them travel grants, food and other items to re-establish a household. The United Nations is also rebuilding about 60,000 homes.

The U.N. program is a dramatic success. Last year, it helped 1.5 million Afghans return - from Pakistan alone.

This year's number looks low by comparison, but U.N. officials say this is not unusual. Jack Redden is the spokesman for the United Nations High Commissioner for Refugees, or UNHCR, in Pakistan.

"Three hundred thousand [from Pakistan] is really quite an exceptional number," he said. "The reason it does not look so impressive is just that we had this phenomenal return last year of 1.5 million, and that was the largest that UNHCR had seen in more than 30 years. So, last year was very abnormal."

As winter in Afghanistan approaches, U.N. officials say the number of refugees returning is expected to decline. Mr. Redden adds that weather is more important than violence in terms of repatriation.

"We are now heading into winter, so the numbers of course are going down," said Mr. Redden. "So, it does not seem to have been affected by the reports of violence in certain parts of the country."

Because of the long and porous border between Afghanistan and Pakistan, a small percentage of the refugees went back to Pakistan after receiving U.N. assistance, only to return to Afghanistan. To deter that, the U.N. aid agency is now using eye-scan machines on refugees getting U.N. assistance. The machine can detect someone who has been tested before. Mr. Redden says this has cut down on abuses.

"I think it has been extremely effective," he said. "We have detected almost none who have tried to go through a second time. We knew that last year, some people, obviously slipped through a second time. So, this has cut out anybody who was not legitimate."

U.N. officials say an estimated one million Afghans are still living in camps in Pakistan, while an unknown but substantial number are living in cities.

In the 23 years of war before the fall of the Taleban regime nearly two years ago, up to five million Afghans fled into exile, most of them to Pakistan and Iran.